be the transmission, as long as there aren't any grinding noises when you put your foot in it or do some engine-braking. I believe the sulfur smell in your TT is from your O2 sensors, mine were bad and caused the same smell on my NA.
Other than the engine and transmission, I would check the power steering lines on the passenger side of the engine. If they leak, they drip right on the alternator and burn it out.